Attention Deficit Hyperactivity Disorder: scaling and standard setting using Rasch measurement

This paper explores the dimensionality of responses to the Adult Behavior Checklist Revised, a screening assessment for Attention Deficit Hyperactivity Disorder (ADHD) in college students, and demonstrates a standard setting process for diagnostic rating scales. Responses from 317 undergraduate college students were used to investigate dimensionality; 8 judges were used for the standard setting procedure. A series of Rasch rating scale analyses support the interpretation of Inattention and Impulsivity/Hyperactivity variables. Principal component analyses of residuals identified the existence of secondary variables that may have clinical implications for the evaluation and treatment of ADHD. For the standard setting process, judges generally displayed less variability than expected by the model. Several judges were in disagreement as to the level of symptomatology needed to indicate potential ADHD. The derived standard for Inattention was found to be more stringent than a previously suggested standard while the derived standard for Hyperactive/Impulsive more lenient. Prevalence rates found a diagnosis of Hyperactive/Impulsive to be more common than a diagnosis of Inattention. Efficient screening assessments for ADHD in college students are needed in order to determine who may qualify for further evaluation and special services. The standard setting process attempts to identify judge disagreement regarding the level of symptomatology (the standard) needed to qualify for additional evaluation and identify judge response strings not consistent with the item difficulties. Recommendations suggesting additional work on the screening assessment and standard setting process are outlined.